Facebook has become about as synonymous with social networking as, well, Google is to search. Like almost every other site, you can search in Facebook, but you wouldn't call it a search site. Conversely, the main Google site isn't a social network though its YouTube property is.

Facebook CEO Mark Zuckerberg has put the company on "lockdown" for 60 days in preparation for a coming war with Google.

The reason: Google will launch a social network called Google Me sometime between tomorrow and the end of the year, according to a very widely accepted but unconfirmed rumor. The company is also buying up companies to fortify itself for the launch.

But why would a search engine company want to dominate social networking? The answer is that Google isn't a search engine company. Google is in the advertising business. It attracts users by offering a wide variety of free services. Google then uses those services to harvest information about users, which it can then leverage to sell more advertising at higher prices.

Facebook is in the exact same business. Facebook offers its free social network, and uses the activity of users to gain insight that helps them sell more and better ads.

Facebook has more than 500 million users, and is growing fast. According to some reports, Facebook sends more traffic to some types of Web sites than Google does. This no doubt threatens Google's intent to dominate the future of online advertising.

To fight back, Google has recently acquired a game-oriented virtual currency company called Jambool, a social gaming company called Zynga and a social networking applications company called Slide. Google had previously acquired the microblogging service Jaiku.

Google has already tried and failed in three ways to create a social network that can compete with Facebook. First, Google launched its social network, called Orkut. While the service became a hit in Brazil, and gained many users in India, the rest of the world responded to Orkut with an underwhelming "meh!"

Second, Google launched its Profiles service, which also failed to catch fire.

And finally, Google launched the social message service Buzz, which was integrated with Profiles.Related Articles# Google Says Goodbye to Wave# Facebook, Open Source and LAMP# Google Accelerates Chrome Development, Security# Social Networks Trounce Email in Study# How Does Social Media Affect the Enterprise?

Together, Profiles and Buzz should and could replace the basic functionality of Facebook. But that's not enough, and people aren't switching.

Facebook has several powerful advantages. It's easier to use for non-technical users. It has more "stuff" to do; it's more feature-complete.

But most of all, Facebook enjoys a critical mass of users. If you want to be where the rest of your family is, you've got to be on Facebook.

Google's various social offerings may be too open -- or, more accurately, too far flung and loosely connected. Users seem to respond better to Facebook's walled garden approach -- it feels like a single destination that you "enter," whereas most of Google's social offerings feel like they're out there on the public Internet.

The smart money is on Google launching its Google Me social network in a way that aims squarely at Facebook's weak spots, which are:

The obvious benefit here is that other people maintain and correct their own information (current phone number, e-mail address and so on). Meanwhile, Google just executed a beautiful revamp of their online Contacts application. We'll see if it's integrated into Google Me.

2. Ease of privacy. Facebook is now famous for confusing and annoying users about privacy and sharing settings. Google is a lot better at this. If Google can make users feel at ease with what they're sharing, where they're sharing it and with whom, they'll hit Facebook where it hurts.

3. Segregation of social networks. Facebook theoretically gives you the ability to corral all your Friends into different groups, then serve them separately. Unfortunately, almost nobody even knows this feature exists, yet the inability to keep personal social networks (friends, family, etc.) from clashing into each other is the number one reason many people leave or ignore Facebook. If Google gets this right, they'll win over a lot of disgruntled Facebook users.

4. Gaming. Games on Facebook probably do Facebook more harm than good. They're a major source of what feels like Facebook "spam," and the games themselves are usually lame. Google's recent acquisition of two social gaming companies suggests they'll seriously attack this Facebook vulnerability.

5. Events. People use Facebook for organizing events of all kinds. But Facebook has nothing as compelling as Google Calendar, which is an extraordinarily useful event-planning and communication tool. If Google could build Google Calendar into Google Me, the invitation process could prove to be a powerful way to introduce people to their social network.

6. Search. Facebook search is horrible. It doesn't seem to index all content. It doesn't sort results intelligently. And it offers an anemic "Web Results" section that isn't appealing to use. Worst of all, it doesn't readily allow you to search content posted by people you don't follow (with their permission, of course).

Google could do for social networks what it did for e-mail: Make it search-centric. Google has already integrated social results into standard Google searches, so the raw materials are already there.

If Google can manage to bring together all its strengths, attack all of Facebook's weaknesses, and do so in a way that satisfies the public's preference for a site that feels like a single, enclosed destination, I think the company has a shot at becoming the new Facebook -- and turning the real Facebook into the new MySpace.